Monga momwe tawonetsera mkuyu. 3, pali njira zitatu zazikulu zomwe zimafuna kupereka SiC single crystal yokhala ndi khalidwe lapamwamba komanso logwira mtima: epitaxy yamadzimadzi (LPE), kayendedwe ka mpweya wa thupi (PVT), ndi kutentha kwapamwamba kwa mankhwala opangidwa ndi nthunzi (HTCVD). PVT ndi njira yokhazikitsidwa bwino yopangira SiC single crystal, yomwe imagwiritsidwa ntchito kwambiri m'mafakitale akuluakulu opanga mawafa.
Komabe, njira zonse zitatuzi zikusintha mwachangu komanso zatsopano. Sizinali zotheka kutsimikizira kuti ndi njira iti yomwe idzavomerezedwe kwambiri mtsogolomu. Makamaka, SiC single crystal yapamwamba kwambiri yomwe imapangidwa ndi kukula kwa yankho pamlingo wokulirapo idanenedwa m'zaka zaposachedwa, kukula kochulukirapo kwa SiC mu gawo lamadzimadzi kumafuna kutentha pang'ono kuposa komwe kumapangidwira kapena kuyika, ndipo kukuwonetsa kuchita bwino popanga P. -mtundu wa magawo a SiC (Table 3) [33, 34].
Chithunzi 3: Schematic ya njira zitatu zazikulu za SiC single crystal kukula: (a) madzi gawo epitaxy; (b) kunyamula nthunzi; (c) kutentha kwambiri kwa nthunzi wa mankhwala
Gulu 3: Kufananiza kwa LPE, PVT ndi HTCVD pakukulitsa makristasi a SiC amodzi [33, 34]
Kukula kwa yankho ndiukadaulo wokhazikika pokonzekera ma semiconductors apawiri [36]. Kuyambira m'ma 1960, ofufuza ayesa kupanga kristalo mu yankho [37]. Tekinoloje ikangopangidwa, supersaturation ya kukula pamwamba imatha kuyang'aniridwa bwino, zomwe zimapangitsa njira yothetsera vutoli kukhala ukadaulo wodalirika wopezera ma ingots apamwamba a kristalo.
Pakukulitsa yankho la SiC single crystal, gwero la Si limachokera ku Si kusungunuka koyera kwambiri pomwe graphite crucible imagwira ntchito ziwiri: chotenthetsera ndi C solute source. Makristalo a SiC amodzi amatha kukula pansi pa chiŵerengero choyenera cha stoichiometric pamene chiŵerengero cha C ndi Si chili pafupi ndi 1, kusonyeza kuchepa kwa chilema chochepa [28]. Komabe, pamphamvu ya mumlengalenga, SiC siwonetsa malo osungunuka ndipo imawola mwachindunji kudzera pa kutentha kwa mpweya kupitirira 2,000 °C. SiC imasungunula, malinga ndi ziyembekezo zongoyerekeza, zitha kupangidwa pansi pazovuta kwambiri kuchokera ku chithunzi cha Si-C bayinare gawo (mkuyu. 4) kuti ndi kutentha kwa gradient ndi njira yothetsera. Kukwera kwa C mu Si kusungunuka kumasiyana kuchokera 1at.% mpaka 13at.%. Kuthamanga kwa C supersaturation, kufulumira kwa kukula, pamene mphamvu yotsika ya C ya kukula ndi C supersaturation yomwe imayang'aniridwa ndi 109 Pa ndi kutentha pamwamba pa 3,200 ° C. Ikhoza supersaturation imapanga pamwamba yosalala [22, 36-38] .kutentha pakati pa 1,400 ndi 2,800 °C, kusungunuka kwa C mu Si kusungunuka kumasiyana kuchokera ku 1at.% mpaka 13at.%. Mphamvu yoyendetsa kukula ndi C supersaturation yomwe imayendetsedwa ndi kutentha kwa kutentha ndi njira yothetsera. Kukwera kwa C supersaturation, kukula kwachangu, pamene kutsika kwa C supersaturation kumapanga malo osalala [22, 36-38].
Chithunzi 4: Si-C binary gawo chithunzi [40]
Doping transition metal element kapena zinthu zosowa zapadziko lapansi sizimangochepetsa kutentha kwa kukula koma zikuwoneka kuti ndiyo njira yokhayo yowonjezerera kusungunuka kwa kaboni mu Si kusungunuka. Kuwonjezera zitsulo gulu kusintha, monga Ti [8, 14-16, 19, 40-52], Cr [29, 30, 43, 50, 53-75], Co [63, 76], Fe [77- 80], etc. kapena osowa nthaka zitsulo, monga Ce [81], Y [82], Sc, etc. kwa Si kusungunula amalola mpweya kusungunuka kupitirira 50at.% m'malo omwe ali pafupi ndi thermodynamic equilibrium. Kuphatikiza apo, njira ya LPE ndiyabwino kwa P-type doping ya SiC, yomwe imatha kutheka pophatikiza Al mu
zosungunulira [50, 53, 56, 59, 64, 71-73, 82, 83]. Komabe, kuphatikizidwa kwa Al kumabweretsa kuwonjezeka kwa resistivity ya P-type SiC single crystals [49, 56] .Kupatulapo kukula kwa mtundu wa N pansi pa doping ya nayitrogeni,
Kukula kwa njira kumapitilira mumlengalenga wa mpweya wa inert. Ngakhale kuti helium (He) ndi yokwera mtengo kuposa argon, imakondedwa ndi akatswiri ambiri chifukwa cha kutsika kwake kwamakamaka komanso kutsika kwa kutentha kwapamwamba (8 times of argon) [85]. Kuchuluka kwa kusamuka ndi Cr zomwe zili mu 4H-SiC ndizofanana pansi pa He ndi Ar atmosphere, zikutsimikiziridwa kuti kukula pansi pa Heresults pakukula kwakukulu kuposa kukula kwa pansi pa Ar chifukwa cha kutentha kwakukulu kwa mwini mbeu [68]. Amalepheretsa mapangidwe a voids mkati mwa kristalo wamkulu ndi nucleation yokhayokha mu yankho, ndiye, morphology yosalala imatha kupezeka [86].
Pepalali linayambitsa chitukuko, ntchito, ndi katundu wa zipangizo za SiC, ndi njira zazikulu zitatu zokulitsira SiC single crystal. M'magawo otsatirawa, njira zamakono zowonjezera zothetsera mavuto ndi zofunikira zogwirizana nazo zinawunikiridwa. Pomaliza, lingaliro linaperekedwa lomwe lidakambirana zovuta ndi ntchito zamtsogolo zokhudzana ndi kukula kwa SiC single crystals kudzera njira yothetsera.
Nthawi yotumiza: Jul-01-2024